Ripened watermelons are generally ripened with plant hormones such as ethephon, resulting in red flesh and white seeds. Regular consumption of fruits with excessive ripening agents is harmful to the body. Watermelons ripened with ripening agents not only have a poor texture but also lack nutritional value, so it is best to eat them in moderation.
In terms of appearance, the flesh of a ripened watermelon is red after being cut, but it is not as uniform as a naturally ripened one. Many of the seeds are also shriveled and white, and the flesh can taste sour when eaten. When stored in the refrigerator, a ripened watermelon will spoil in about two days, unlike naturally ripened watermelons, which can be kept for more than a week.
When selecting a watermelon, you can pay attention to its aroma. The skin of a naturally ripened watermelon usually has a melon-like fragrance, whereas a ripened one may have no smell or even an off-odor. Due to sufficient sunlight, naturally ripened watermelons often have a deep, bright color, clear stripes, and a firm, old stem. In contrast, the skin of a ripened watermelon is a fresh, light color with faint stripes and a green stem.